The Icelandic volcano, whose eruption has thrown regional air travel into disarray, is capable of the persistent activity which could have an impact on crop production.

Analysts at World Weather, the US-based meteorological service, have said that the Eyjafjallajokull volcano presents little threat in the short-term of changing world weather patterns.

The reaction to the eruption, including the suspension of air travel in and out of the UK, has exaggerated the significance of the incident.

"It is highly doubtful that anything more than enriched sunsets and sunrises will come out of this eruption," World Weather president Drew Lerner said.

A US crop analyst told Agrimoney.com: "The real danger is from volcanoes on the equator. Those away from there in northern latitudes don't tend to cause so much trouble."

'Still early on'

However, that benign outlook might change if the eruption persists "with the kind of intensity it did earlier today over an extended period of time", he said.

"It is still early on."

And the volcano is capable of prolonged activity, scientists at America's Smithsonian Institution said, noting that the last eruption, which started in December 1821, did not finish until January 1823.

The Smithsonian has warned that Eyjafjallajokull poses a bigger danger if its activity melts glaciers on Katla, a neighbouring volcano, which has proved capable of more significant eruptions.